Present study explores cultural issues of the professional helper’s intervention on the incest family. Taking the cases from Atayal family and focusing the incidents of incest, presents study revealed the cultural issues of professional helper’s intervention and identified how Atayal culture impacts on the family behaviors and thoughts via these critical incidents and suggested the multiple cultural ability of the professional helper. Present study approached three Atayal families, their social workers, and consulters by convenient sampling. These cases were in-depth interviewed and the recordings were carefully transcribed. The researcher and another coordinating coder analyzed the transcripts into meaningful units via open coding. The meaningful units were categorized based on the similarity as categorical units. Finally, we selective coded as themes and reported here with three within-case findings and between-case comparison. The finding indicates the culture of the incented family and the interactive relationship among the family members are threefold: First, incest is a taboo of gaga. Second, bodily touch is a sign of intimacy and friendliness. Third, people who disobey gaga cannot get along with others and would be condemned. The cultural issues of professional helper’s intervention in the aboriginal family were fourfold: First, the best interest of the survivals: safety versus cultural identity. Second, the difference on resolutions: national law versus habitual law. Third, the different understandings of boundary: privacy versus bodily touch as signs of intimacy and friendliness. Fourth, the dilemma of confidentiality: family-centered versus tribe as subject. Finally, the implications of our findings and future research are discussed.